JoVE Logo

Accedi

Capitolo 6

Sostituzione nucleofila e reazioni di eliminazione degli alogenuri alchilici

Alogenuri alchilici
Alogenuri alchilici
Structural Properties Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as ...
Reazioni di sostituzione nucleofila
Reazioni di sostituzione nucleofila
Historical perspective In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a ...
Nucleofili
Nucleofili
The word “nucleophile” has a Greek root and translates to nucleus-loving. Nucleophiles are either negatively charged or neutral species with a ...
Elettrofili
Elettrofili
This lesson explains the definition, classification, and characteristic features of an electrophile that are key features of nucleophilic substitution ...
Gruppi uscenti
Gruppi uscenti
The nature of leaving groups strongly influences the outcome of a nucleophilic substitution reaction. In general, in a nucleophilic substitution reaction, ...
Carbocationi
Carbocationi
Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an ...
Reazione S<sub>N</sub>2: cinetica
Reazione SN2: cinetica
Kinetic Studies and Significance In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction ...
Reazione S<sub>N</sub>2: meccanismo
Reazione SN2: meccanismo
The kinetic studies of SN2 reactions suggest an essential feature of its mechanism: it is a single-step process without intermediates. Here, both the ...
Reazione S<sub>N</sub>2: stato di transizione
Reazione SN2: stato di transizione
An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between ...
Reazione S<sub>N</sub>2: stereochimica
Reazione SN2: stereochimica
In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the ...
Reazione S<sub>N</sub>1: cinetica
Reazione SN1: cinetica
In an SN2 reaction, the reaction rate depends on both the type of nucleophile and the substrate. A hindered tertiary alkyl halide is practically inert to ...
Reazione S<sub>N</sub>1: meccanismo
Reazione SN1: meccanismo
Kinetic studies of ionization of a tertiary halide in a protic solvent suggest that only the substrate participates in the rate-determining step (slow ...
Reazione S<sub>N</sub>1: stereochimica
Reazione SN1: stereochimica
This lesson provides an in-depth discussion of the stereochemical outcomes in an SN1 reaction. In the first step of an SN1 reaction, the bond between the ...
Predire i prodotti: S<sub>N</sub>1 vs. S<sub>N</sub>2
Predire i prodotti: SN1 vs. SN2
Nucleophilic substitution reactions of alkyl halides can proceed via an SN1 or an SN2 mechanism. While in SN2 reactions, the nucleophile attacks the ...
Reazioni di eliminazione
Reazioni di eliminazione
A nucleophile can react with an alkyl halide to give the substitution product by displacing the halogen. Or it can function as a base to give the ...
Reazione E2: cinetica e meccanismo
Reazione E2: cinetica e meccanismo
SN2 substitutions and E2 eliminations of alkyl halides proceed via a concerted pathway. While the nucleophile attacks the alpha carbon in SN2 reactions, ...
Reazione E2: stereochimica e regiochimica
Reazione E2: stereochimica e regiochimica
Elimination reactions of alkyl halides can yield one or more alkenes depending on the specific regiochemical and stereochemical considerations. While the ...
Reazione E1: cinetica e meccanismo
Reazione E1: cinetica e meccanismo
Here, in contrast to the E2 reaction mechanism, we delve into the aspects of the E1 reaction mechanism, which has two steps: rate-limiting loss of the ...
Reazione E1: stereochimica e regiochimica
Reazione E1: stereochimica e regiochimica
One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. ...
Predire i prodotti: sostutuzione vs. eliminazione
Predire i prodotti: sostutuzione vs. eliminazione
When a nucleophile and an alkyl halide react, nucleophilic substitution and β-elimination reactions compete to generate products. The following ...
JoVE Logo

Riservatezza

Condizioni di utilizzo

Politiche

Ricerca

Didattica

CHI SIAMO

Copyright © 2025 MyJoVE Corporation. Tutti i diritti riservati